# Stories from week 5

I teach once-a-week sophomore propositional logic. We are looking at categorical propositions. This week we examined “obverses” – if we change the quality (negative to positive or vice versa) and replace the predicate with its complement, we get a logically equivalent statement (ex. Some birds are not flying animals is equivalent to Some birds are not non-flying animals, or All cows are herbivores is equivalent to No cows are non-herbivores.) As I asked for questions and explanations a boy began explaining how complementary colors work – right word, wrong context. I began correcting the misunderstanding but he dug in, and finally he realized the mistake, and he was mortified. Note: I have only met this group five times and barely know them. Later he saw me in the hall and said something about enjoying the class or understanding it so well or some such – he didn’t realize that he was giving me a second chance to reassure him, an opportunity I’d missed in class, and which I eagerly took this time. He was trying to make himself feel better, but he ended up making us both feel better.

A new math teacher asked me about the new student I transferred into her Matrices class. New student? No, there were no new students. Turns out a boy, an athlete actually, preferred taking unnecessary math quizzes over showing up to PE class. used a pseudonym. Got a 100. Won’t happen again.

An alum, college sophomore, showed up after school Thursday. Anthropology / Archaeology major. Great dual major I think. “Great Dual Major! In fact…” I stopped a student of mine “What did we learn about in class today?” “Matrices” “No, besides, math” “Oh, right, if a skeleton was cannibalized, how to tell if it was ritual cannibalism, or for survival” “Thank you…. See, I taught about your major today!” I stopped another student, same question “About how if someone was eating a body for food they would break open the phalanges for the stuff inside” “See!” and over the alum’s objections I stopped one more “What did we learn about today, besides math?” “Nothing. I don’t know” “No, don’t you remember, there was land use in southwest Wisconsin…” “No, we didn’t talk about that” I’d picked a kid from the wrong class.

“Combinatorics” is my favorite class. And it’s more fun when the kids like it, too. We meet four times a week. Three days this week I had to tell the students to leave more than once….